This invention relates generally to improvements in methods and apparatus for filtering out noise, such as electromagnetic interference and, more particularly, to a new and improved system for tailoring the noise suppression characteristics of electronic packages, such as voltage and/or current transient protection devices and the like.
A good deal of modern electrical systems, and especially computers and other circuits employing semiconductor devices, have operating characteristics which render such electrical systems relatively vulnerable to the deleterious effects of electrical transients. For this reason, it has become a common practice in the electrical arts to utilize a transient voltage and/or current protection device to minimize the risks associated with such undesired electrical transients.
While the use of transient protection devices is now commonplace, a new villian has arisen to further complicate matters in terms of interfering with the operation of sensitive equipment such as computers and the like. This problem concerns undesirable electrical noise and typically involves electromagnetic interference commonly referred to as EMI. In this regard, the suppression of electrical transients does not necessarily provide any noise suppression and, at best, any noise suppression that may occur would be rather haphazard and totally unrelated to the actual noise spectrum which should be suppressed in any given situation. Indeed, such noise suppression problems may be encountered not only with transient protection devices, but with other electrical packages as well.
Hence, those concerned with the development and use of electrical packages, including transient protection devices, have long recognized the need for improved methods and apparatus for noise suppression and, more particularly, for selectively tailoring the noise suppression characteristics of electronic packages to suit specific applications. The present invention clearly fulfills this need.